I don't think he is a Chocolate Tan.
I can't tell for sure if it's the mouse or the photo but he looks like he might have a pointed nose and he resembles my burmese does.
Did you breed him yourself or is he from an outside source? Could you maybe post some more pictures?
I'm thinking he's a Chocolate Roan, what with the belly the color and configuration it is. I also agree with others, don't think he's Satin either...he does have a nice, shiny, healthy coat, but Satin mice have noticeably shiny feet, ears and his belly would be shiny too. His belly is telling me he is not Satin.
He was sold to me as satin,but I really wasnt sure he was,but Im new at coat types besides standard,lol.
I dont see how he can be in better condition then the other mice though. Everything is the same for them.
His coat is slightly longer then the others and is more glossy.
He doesnt have white in his top coat though, so could he be roan?